Third to



(No Model.) I J. R. DAVIS.

ELBGTRIG HEATING RUG. v No. 543,800. Patented July 30, 1895.

WITNESSES. lNVE/VTOR BX beau/ Q ATTORNEYS.

1 m: ncRRls PETERS C0,, WASNINGYGN. 04 c.

ATENT ri icn,

.inssn it. DAVIS, or 'PARKERSBURG,

WEST VIRGINIA, ASSIGNOR OF ONE- THIRD TO CHARLES A. VIADE, OF SAME PLACE.

E'LECTREC HEATlNG-RUG.

SPEGIFIGATION foimingpart of Letters Patent No. 543,800, dated July 30, 1895.

Application filed July 11, 1894.

To all whom it may concern:

Be it known that l, JESSE R. DAVIS, of Pan kersburg, in the county of Wood and State of West Virginia, have invented a new and use- 5 ful Improvement in Electric Heating-Rugs, of which the following is a specification.

My invention is in the nature of an electric rugfor heating or warming the feet, for use in private residences or under the desks in to offices, for the floors ofstreet cars, for stalls in the market,- the floors of carriages, or any other application where a stove is inconvenient or impracticable and yet there is great need for some means for keeping the .feet is warm.

My invention consists of a fiat rug designed to lie upon the floor and having a surface of carpet or other textile, or without such surface, if desired, and combining in-its internal structure an electrical heating medium and two electrodes of special form and arrangement, and also a distributing and protecting. plate, and with means for insulating the cur-' rent and retaining the heat as it is trans formed from electrical energy by the resistance of the heating medium, as will be here'- inafter more fully described.

Figure 1 is a plan view of the rug with the upper portion removed. Fig. 2' is'a vertical central section. a

A is the outer case of the rug, which maybe made of wood, canvas covered with asbestos, composite woody-fiber of non-conductingqual- -ity, papier-mach, leather-board, leather, hard 5 rubber, or even of porcelain, slate, fire-clay,

tile, or enameled sheet metal. As shown, the" case is round and shallow, with a raised flange around its circular edge to retain the heating medium, The rug may, however, be made of, any-desired shape. The case is about two and one-half inches deep and is filled with a heating material C, which is preferably a composite mixture of powdered 'plumba'g'o and any inert andrefractory material, such as fire-clay, lixne, orany powdered material that is both a nonconductor of electricity and a non-conducting and heat-resisting material. The proportions in which the electricallyconductive plumbago is mixed with the inert and refractory material determines the are No. 517,225. on model.)

the proportion of plumbago the higher the degree of heat that will be obtained. For ordinaryusesfrom ten to aboutthirty-eight,

per cent. of plumbago would be used and the balancebe of refractory material.

E is one of, the electrodes, which is made ring-shaped and ot a triangular cross-section, This ring is embedded in the heating medium,

near the outer edge of the same, with one of its fiat sides at the'top and a sharp edge penetrating downwardly with the heating medium. D is the other electrode, which isconstructed as a conical plate, with its fiat base at the top and its apex penetrating downwardly into the heating medium. The object in-making the electrodes of this shape is to cause them to penetrate the heating medium with a'tightwedging action from the pressure of the feet on the top of the rug, so as -toalways insure an intimate electrical contactbetween the electrodes and the heating medium. The electrode D should be exactly in the center of the ringshaped electrodes E in order to preserve a u'nit'ornf'radial distribution of the current through the heating medium, it being obvious that if. the electrodes were not concentriethe bull; of the current would pass between-their sides which most closely appreach, which wouldresultjju a lack of uni the top of both electrodes and having a layer transforming from the current. The greater P of mineral wool, asbestos, or other non-conductor above it and another similar layer P below. it to prevent metallic connection between the electrodesg- -llhis sheet-metal plate K-protects the heating medium and electrodes when walking upon the rug, thus avoiding the disintegrating of the heating medium and displacement of the electrodes. This plate K also acts as a distributor of the heat, causing the upper-surface of the rug to be uniformly warm. I

Overt-he padding P, of mineral wool or asbestos," is anoutside covering B, of Brussels carpet or any other fabric or material, which is fastened around the edges with an orha IOO casing.

mental nickel-plated rim '1", secured by nails, screws, or bolts to the flange of the outer To facilitate the moving of the rug from place .to place rollers or casters '5 are secured to its bottom side.

This invention will prove a great relief to old person's, invalids, and others sulfering with cold feet or rheumatism.

Having thus described my invention, What I- claim as nevrgand desire to secure by Letters Patent, is-

1. An electric heating rug, comprising a-fiat layer of electric heating medium of amorphone resistingmaterial, a ring-shaped electrode of triangular cross section having its fiat face uppermost, a second electrode of conical shape arranged with its base uppermost and in concertric relation to the ring, both being arranged in the sameplane in the heating medium, and an insulating casing with flexible covering, substantiallyas and for the purpose described.

2. An electric heater comprising a casing containing a resistance material, two electrodes arranged concentrically therein, and a metalliedistsibuting plate' extending "entirely across both electrodes and P lyinsulatecl therefrom substantially as shown and described.

JESSE R. DAVIS.

Witnesses;

E. L. NASHL J. HKNAPP. 

